#include <iostream>

using namespace std;

void swap(int &a, int &b)
{
        int tmp;
        tmp = a;
        a = b;
        b = tmp;
}

int main()
{
        int a = 4, b = 6;

        swap(a, b);
        cout << "a = " << a << ", b = " << b << endl;

        return 0;
}
